1. Field of the Invention
The present invention relates to a head chip, a liquid jet head, and a liquid jet recording apparatus.
2. Description of the Related Art
As a liquid jet recording apparatus, there is known an ink jet type recording apparatus which jets ink, functional liquid, or the like onto a recording medium or the like to record a predetermined pattern such as text or graphics. This inkjet type recording apparatus is configured to, for example, supply liquid such as ink or functional liquid from a liquid tank via a supply tube to a liquid jet head, fill a liquid jet channel provided in the head chip with the liquid, deform the liquid jet channel by application of voltage, and jet the filled liquid from a nozzle communicating thereto by the change in capacity by the deformation.
In an inkjet recording apparatus disclosed in Japanese Patent Application Laid-open No. Hei 6-143602, as an ink supply system for supplying ink to an ink jet head, there is adopted a circulating system which circulates ink between the ink jet head and an ink tank. The ink jet head has a channel on the head inner side with respect to a nozzle array. An ink supply flow path is connected to one end side of the channel, and an ink discharge flow path is connected to the other end side of the channel. Ink is supplied from the ink supply flow path to the channel, and part of the ink is jetted from a nozzle by actuation of an oscillator. The excess ink is returned through the ink discharge flow path to the ink tank.
By the way, in an ink jet head with an ink circulating system using a liquid flow path having a flow inlet and a flow outlet of ink as mentioned above, difference in pressure is caused between the flow inlet side and the flow outlet side due to pressure loss in the head. Therefore, difference in volume is caused between a nozzle which is near the flow inlet and a nozzle which is near the flow outlet when ink is jetted, and the volume of ink gradually reduces in the order of the nozzles. Thus, there is a problem that density gradation appears in the direction of the nozzle array (direction of extension of the nozzle array) to affect the image quality.
In particular, when a plurality of ink jet heads are arranged side by side in the direction of extension of the nozzle array, a nozzle which is near the flow outlet and has a small ink volume and a nozzle which is near the flow inlet and has a large ink volume are arranged so as to be adjacent to each other. Then, the density contrast between the nozzles is conspicuous, and thus, there is a problem that the contrast appears as streaks between the ink jet heads to affect the image quality.